Hi Sade's and welcome to the forum.
As others have said, it's just a set back but please don't give up too quickly. You will soon get the hang of vaping. We're a really friendly bunch on here and all try to help each other. Most of us are just end users so we're not going to try to sell you anything either.
I know it may seem like a lot of messing around when you first start but if you persevere with it you'll be so glad in the end because it is definitely worth it. I've been vaping 7 years and I'm enjoying it so much wild horses couldn't drag me back to smoking again.
Since you bought both devices, are you both vaping the same ejuice or have you bought different flavours?
The reason I ask is because the ratio of PG and VG in the liquid may be different between different bottles.
Above the USB charging port you have a second button which adjusts the power setting and it may be that yours is on a higher setting than your husbands so you just have to keep pressing it to scroll through the settings to choose the one you like. There are 4 different settings which are:-
M = Mild.
S = Soft.
N = Normal.
H = Hard.
As
@KytanDale said, as you are just starting out the 1.4ohm coil is the best one to start out on and with that type of coil you want the juice to be slightly higher in PG (propylene glycol) content and up to 12 mg nicotine.
When you use the other coils they are sub ohm coils which means the coil resistance is less than 1 ohm and for those you need to use different juice which has less PG and also less nicotine or it will be too harsh but for the time being just forget about those coils and stick to the 1.4ohm to get going.
As for leaking, yes vaping can get messy until you learn the right ways to prevent it happening but be patient and you'll figure it out pretty quickly.
The coils just push in and pull out so they are really easy to change. On the new coils there are 2 o-rings so first make sure you can see both of them are on and don't appear damaged at all.
When you are putting in a brand new unused coil it's a good idea to prime the coil first by just getting your juice bottle and putting a few drops onto the little holes on the side of the coil where you can see the cotton showing through.
Now you can push the coil into the tank so make sure the coil is firmly pushed all the way in.
Now screw on the bottom of the tank nice and firnly.
When it's time to refill first make sure you close the air holes by turning the ring on the bottom of the tank. Then unscrew the drip tip and put the juice into one of the little kidney shaped holes on the side but you must not put juice down the centre.
Once it's filled screw the drip tip back on.
Now a little tip that sometimes helps on other tanks is before you open the air holes again use a tissue to catch any excess juice in the coil and turn the tank upside down and then open the air hole. That gives the air pressure and vacuum in the tank a chance return to normal which sometimes helps prevent leaks.
If the coil is new let it stand for about 10 - 15 minutes before you try vaping it to allow the cotton to soak up enough juice and also it's a good idea to go the the lowest mild setting so you don't singe the cotton or it will taste burnt. When you're happy that the flavour is coming through nicely then you can turn the setting up to where you like it.
Another thing that is good practice with a lot of tanks is to close the air holes overnight. In the morning, use a little tissue and turn the tank on its side holding the tissue against one of the holes as you open the air holes again so you can catch any juice that may have leaked.
If you have any more questions we will always be more than happy to help out so ask anything you want.
Good luck and I hope all this has helped.